A possible postsynaptic role for SNAP-25 in hippocampal synapses.

The SNARE protein SNAP-25 is well documented as regulator of presynaptic vesicle exocytosis. Increasing evidence suggests roles for SNARE proteins in postsynaptic trafficking of glutamate receptors as a basic mechanism in synaptic plasticity. Despite these indications, detailed quantitative subsynaptic localization studies of SNAP-25 have never been performed. Here, we provide novel electron microscopic data of SNAP-25 localization in postsynaptic spines. In addition to its expected presynaptic localization, we show that the protein is also present in the postsynaptic density (PSD), the postsynaptic lateral membrane and on small vesicles in the postsynaptic cytoplasm. We further investigated possible changes in synaptic SNAP-25 protein expression after hippocampal long-term potentiation (LTP). Quantitative analysis of immunogold-labeled electron microscopy sections did not show statistically significant changes of SNAP-25 gold particle densities 1 h after LTP induction, indicating that local trafficking of SNAP-25 does not play a role in the early phases of LTP. However, the strong expression of SNAP-25 in postsynaptic plasma membranes suggests a function of the protein in postsynaptic vesicle exocytosis and a possible role in hippocampal synaptic plasticity.

Correction to: A possible postsynaptic role for SNAP-25 in hippocampal synapses.

In the original publication of the article the author name M. Schupps was incorrect.

A new case of Carney triad: gastrointestinal stromal tumours and leiomyoma of the oesophagus do not show activating mutations of KIT and platelet-derived growth factor receptor alpha.

The Carney triad is a rare syndrome of unknown aetiology, with synchronous or metachronous appearance of rare neoplasms: gastrointestinal stromal tumours (GISTs), pulmonary chondromas and extra-adrenal paragangliomas. In most cases, the Carney triad is incomplete. The combination encountered typically, GISTs and pulmonary chondromas, was also seen in our patient, a 22-year-old woman. She was diagnosed with the triad after Billroth II gastrectomy for histologically proved gastric GISTs. The diagnosis of pulmonary chondromas was confirmed by transthoracic, computed tomography-guided needle biopsy. An oesophageal leiomyoma was resected 2 years after the initial diagnosis, on suspicion of paraganglioma. The clinical course of the patient has been uneventful since. The last follow-up was carried out 6 years after the initial diagnosis. On histological examination, the cells of gastric GIST were partly positive for CD34, whereas CD117 was expressed in all areas in variable intensity and S-100 protein was negative. The oesophageal tumour was classified as leiomyoma due to strong immunopositivity for smooth muscle actin and desmin, being negative for CD34 and CD117. Two different gastric GIST lesions as well as the oesophageal leiomyoma and normal tissue were analysed for activating mutations in common hot spots of KIT (exon 9 and 11) and platelet-derived growth factor receptor alpha (exon 18), but in all probes wild-type sequences were found. These results are in accordance with the first published analyses of GIST lesions from Carney patients.

Changes in response properties of rostral ventromedial medulla neurons during prolonged inflammation: modulation by neurokinin-1 receptors.

Activation of neurokinin-1 (NK-1) receptors in the rostral ventromedial medulla (RVM) can facilitate pain transmission in conditions such as inflammation, and thereby contribute to hyperalgesia. Since blockade of NK-1 receptors in the RVM can attenuate hyperalgesia produced by prolonged inflammation, we examined the role of NK-1 receptors in changes of response properties of RVM neurons following four days of hind paw inflammation with complete Freund's adjuvant. Recordings were made from functionally identified ON, OFF and NEUTRAL cells in the RVM. Spontaneous activity and responses evoked by a series of mechanical (10, 15, 26, 60, 100, and 180 g) and heat (34-50 °C) stimuli applied to the inflamed and non-inflamed hind paws were determined before and at 15 and 60 min after injection of the NK-1-antagonist L-733,060 or vehicle into the RVM. Prolonged inflammation did not alter the proportions of functionally-identified ON, OFF and NEUTRAL cells. ON cells exhibited enhanced responses to mechanical (60-100g) and heat (48-50 °C) stimuli applied to the inflamed paw, which were attenuated by L-733,060 but not by vehicle. Inhibitory responses of OFF cells evoked by mechanical stimuli applied to the inflamed paw were also inhibited by L-733,060, but responses evoked by stimulation of the contralateral paw were increased. Heat-evoked responses of OFF cells were not altered by L-733,060. Also, neither L-733,060 nor vehicle altered spontaneous ongoing discharge rate of RVM neurons. These data indicate that NK-1 receptors modulate excitability of ON cells which contribute to both mechanical and heat hyperalgesia, whereas NK-1 modulation of OFF cells contributes to mechanical hyperalgesia during prolonged inflammation.

Long-term oxygen therapy: financial and future consideration.

Many persons with lung disease require the use of supplemental low-flow oxygen, which has been shown to reduce the physiological effects of hypoxemia, increase exercise tolerance, and improve t he user's sense of well-being. This article discusses three systems used for long-term delivery of oxygen, the financial considerations of these systems, and developments in the new technology of oxygen-conserving devices, which may decrease oxygen consumption and costs while providing increased comfort and mobility for users.

High-precision direct measurements of (13)CH(4)/(12)CH(4) and (12)CH(3)D/(12)CH(4) ratios in atmospheric methane sources by means of a long-path tunable diode laser absorption spectrometer.

Measurements of (13)CH(4)/(12)CH(4) and (12)CH(3)D/(12)CH(4) ratios in atmospheric methane (CH(4)) sources provide important information about the global CH(4) budget as well as about CH(4) production and consumption processes occurring within the various sources. As an alternative to the conventional mass spectrometer (MS) technique, which requires conversion of CH(4) to CO(2) and H(2), we have developed a tunable diode laser absorption spectrometer (TDLAS), which permits rapid direct measurements of the (13)CH(4)/(12)CH(4) and (12)CH(3)D/(12)CH(4) ratios. An intercomparison between TDLAS and MS techniques for samples from natural wetlands, landfills, and natural gas sources resulted in a mean deviation of Δδ(13)C = 0.44‰ and ΔδD = 5.1‰. In the present system the minimum mixing ratios required are 50 parts in 10(6) by volume (ppmv) CH(4) (sample size 2 µmol CH(4)) for direct δ(13)C measurements and 2000 ppmv (sample size 80 µmol CH(4)) for direct δD measurements. These mixing-ratio limits are adequate for most CH(4) source characterization studies without requiring sample preconcentration.

Capecitabine in patients with breast cancer relapsing after high-dose chemotherapy plus autologous peripheral stem cell transplantation--a phase II study.

Capecitabine, a tumor-selective, oral fluoropyrimidine, has demonstrated significant antitumor activity in patients with metastatic breast cancer. In this open-label monocenter phase II study the efficacy and safety of capecitabine in patients with metastatic breast cancer who relapsed after high-dose chemotherapy was examined. Female patients 18-65 years of age, with a histologically confirmed diagnosis of metastatic breast cancer, who relapsed after high-dose chemotherapy (adjuvant and/or metastatic) followed by autologous peripheral blood stem cell transplantation (PBSCT) and who had been treated in their course of the disease with an anthracycline and/or an anthracycline/taxane containing regimen were included into this clinical study. Capecitabine was applied as the first salvage chemotherapy at relapse after high-dose chemotherapy (1250 mg/m(2) b.i.d. p.o. for 14 days followed by 7 days rest period). Responding patients or those with stable disease after two treatment cycles were offered to continue treatment until tumor progression. Response rate, time to disease progression, survival, toxicity and quality of life were assessed. Fourteen patients between 35 and 60 years (median 45.5 years) entered this study and received a median number of 5 cycles (range 1-19) of capecitabine. All patients were evaluable for response. All patients had been pretreated with 1-2 cycles of high-dose chemotherapy plus PBSCT. Furthermore, 13 patients had additionally received local radiotherapy. On average, the patients showed metastatic disease in two organ sites (range 1-4 sites). One patient obtained a complete response and five patients a partial response, accounting for a response rate of 42.9% [95% confidence interval (17.7%; 71.1%)]. All responses were already achieved at the first observation time point 6 weeks after treatment initiation. Two further patients obtained stable disease for at least 12 weeks. At the time of final analysis all patients have progressed. Median time to progression was 2.8 months (range 0.4-13.3 months). No median survival time was reached (range 3.9-36.5 months, at the time of reporting eight patients were alive and six patients had died). Two patients developed grade III granulocytopenia. Five patients developed grade III hand-foot syndrome. One patient had the combination of nausea, fever and diarrhea grade III. All adverse events were considered manageable. We conclude that capecitabine as single-agent oral chemotherapy is active and well tolerated in heavily pretreated patients with breast cancer. It can be safely used in patients who have been intensively pretreated by myelotoxic chemotherapy or who have even relapsed after high-dose chemotherapy with PBSCT.

Excessive iron storage in a patient with Wilson's disease.

We report on an otherwise healthy female, mother of two children, with severe decompensated liver cirrhosis due to an iron overload and Wilson's disease. The patient was considered heterozygote for hemochromatosis on the basis of the autosomal recessive inheritance for hemochromatosis, the frequency of the hemochromatosis gene, and the laboratory parameters defining her iron overload. The case is interesting because of the coincidence of Wilson's disease and excessive iron storage.

Postoperative extracorporeal membrane oxygenation for severe intraoperative SIRS 10 h after multiple trauma.

A 34-yr-old male suffered multiple trauma in a road traffic accident. He required right thoracotomy and laparotomy to control exanguinating haemorrhage, and received 93 u blood and blood products. Intraoperatively, he developed severe systemic inflammatory response syndrome (SIRS) with coagulopathy and respiratory failure. At the end of the procedure, the mean arterial pressure (MAP) was 40 mm Hg, arterial blood gas analysis showed a pH of 6.9, Pa(CO(2)) 12 kPa, and Pa(O(2)) 4.5 kPa, and his core temperature was 29 degrees C. There was established disseminated intravascular coagulation. The decision was made to stabilize the patient on veno-venous extracorporeal membrane oxygenation (ECMO) only 10 h after the accident, in spite of the high risk of haemorrhage. The patient was stabilized within 60 min and transferred to the intensive care unit. He was weaned off ECMO after 51 h. He had no haemorrhagic complications, spent 3 weeks in the intensive care unit, and has made a good recovery.

Expression of CD44 splice variants in squamous epithelia and squamous cell carcinomas of the head and neck.

Splice variants of the adhesion molecule CD44 have been described as essential for the lymphatic spread of rat tumour cells and are claimed to be involved in the metastatic spread of several human tumours. Immunohistochemistry has been used to analyse the expression pattern of CD44 standard (CD44s) and variant (CD44v) isoforms in normal and dysplastic squamous epithelia, as well as in primary and metastatic squamous cell carcinomas (SCCs), which spread predominantly by way of the lymphatic system. Frozen sections of squamous epithelia and of squamous cell carcinomas were stained with a panel of monoclonal antibodies recognizing epitopes of CD44s as well as of the variant exons v5, v6, v7, v7-v8, and v10. The stratum basale and stratum suprabasale of squamous epithelia stained with all antibodies; the stratum spinosum stained with anti-CD44v5, anti-CD44v6, anti-CD44v7-8 and anti-CD44v10; the lower layers of the stratum corneum stained with anti-CD44v5. This expression profile was seen in epithelia of the lip, the tongue, the gingiva, the hard palate, the floor of the mouth, the buccal mucosa, and the pharynx. The same pattern of expression was also noted in dysplastic epithelia, but expression of the variant exons v7, v8, and v10 was significantly downregulated in primary squamous cell carcinomas and was not detected at all in the majority of metastasis-derived specimens. Expression of CD44v5 and CD44v6, on the other hand, was mainly unaltered. Thus, epithelial cell layers representing different stages of differentiation express distinct sets of CD44 variant isoforms, where especially exons v8-v10 might be required for the maintenance of the structural integrity of squamous epithelium. Downregulation of these exons on tumour cells could indicate that they are irrelevant for tumour progression or may even hamper infiltration of surrounding tissue or of lymphatics.